libs: display: wayland: add gst_vaapi_display_wayland_new_with_va_display()

Implements new API function so that users could create GstVaapiDisplay
with their own VADisplay within a native display as backend.

https://bugzilla.gnome.org/show_bug.cgi?id=705821

gst-libs/gst/vaapi/gstvaapidisplay_wayland.c

@@ -350,6 +350,35 @@ gst_vaapi_display_wayland_new_with_display (struct wl_display * wl_display)
           NULL), GST_VAAPI_DISPLAY_INIT_FROM_NATIVE_DISPLAY, wl_display);
 }
 
+/**
+ * gst_vaapi_display_wayland_new_with_va_display:
+ * @va_display: a VADisplay #va_display
+ * @wl_display: an Wayland #wl_display
+ *
+ * Creates a #GstVaapiDisplay based on the VADisplay @va_display and
+ * the Wayland @wl_display display.
+ * The caller still owns the display and must call
+ * wl_display_disconnect() when all #GstVaapiDisplay references are
+ * released.
+ *
+ * Return value: a newly allocated #GstVaapiDisplay object
+ */
+
+GstVaapiDisplay *
+gst_vaapi_display_wayland_new_with_va_display (VADisplay va_display,
+    struct wl_display * wl_display)
+{
+  GstVaapiDisplayInfo info = {
+    .va_display = va_display,
+    .native_display = wl_display,
+  };
+
+  g_return_val_if_fail (wl_display, NULL);
+
+  return gst_vaapi_display_new (g_object_new (GST_TYPE_VAAPI_DISPLAY_WAYLAND,
+          NULL), GST_VAAPI_DISPLAY_INIT_FROM_VA_DISPLAY, &info);
+}
+
 /**
  * gst_vaapi_display_wayland_get_display:
  * @display: a #GstVaapiDisplayWayland

gst-libs/gst/vaapi/gstvaapidisplay_wayland.h

@@ -41,6 +41,10 @@ gst_vaapi_display_wayland_new (const gchar * display_name);
 GstVaapiDisplay *
 gst_vaapi_display_wayland_new_with_display (struct wl_display * wl_display);
 
+GstVaapiDisplay *
+gst_vaapi_display_wayland_new_with_va_display (VADisplay va_display,
+    struct wl_display * wl_display);
+
 struct wl_display *
 gst_vaapi_display_wayland_get_display (GstVaapiDisplayWayland * display);